GENETIC STUDIES ON REPRODUCTION TRAITS IN CROSSBRED JERSEY CATTLE IN WESTERN ODISHA

The present study was conducted on 412 crossbred (Jersey X Deshi) cows sired by 24 bulls, maintained over the period from 2005 to 2014. The economic traits studied were age at first calving (AFC; months), calving interval (CI; days), dry period (DP; days) and service period (SP; days). The averages for AFC, CI, DP and SP were 34.46±0.22 months, 505.95±3.24, 224.20±3.31 and 228.26±3.21 days, respectively. Effect of management system was significant for all the economic traits (AFC, CI and DP) except SP. It may be inferred that rearing crossbred Jersey cows under intensive system of management may be advocated to utilize the maximum genetic potential of crossbred cattle for all the traits. Semi-intensive system may help moderate exploration of the traits. But exclusively pasture dependent management should be avoided for rearing crossbred Jersey cows. Heritability estimates for AFC, CI and DP were found to be 0.462 ±0.179; 0.062 ±0.088; 0.270 ±0.138, respectively. Genetic correlations of AFC with CI and SP were high and positive. For maximum genetic improvement and their correlated response, it is necessary to include all the economic traits with differential weightage for achieving accuracy in selection programs.